Verification of 3D-printed universal smartphone retinal imaging adapter against conventional fundus camera imaging for diabetic retinopathy screening

Abstract

Introduction: Screening for diabetic retinopathy (DR) is critical in preventing visual loss. However, current tools are expensive, bulky and sensitive, thus limiting screening coverage, especially in developing areas such as the interior of Borneo. Smartphone-assisted devices may provide an alternative and this study seeks to determine the level of agreement between a smartphone retinal imaging adapter (SRIA) against conventional ones.

Materials and methods: This was a cross-sectional study with Institutional Review Board approval from the Medical Ethics Board of University of Malaya Medical Centre. A total of 284 eyes from 142 patients included underwent retinal imaging using a conventional fundus camera and the SRIA. The images were graded according to Early Treatment of Diabetic Retinopathy Study (ETDRS) classification. Agreement between both modalities was calculated using Cohen’s Kappa statistics.

Results: The Kappa agreement between SRIA and conventional fundus imaging in grading individual ETDRS stages stood at 0.648 (p < 0.001), achieving up to 0.752 (p < 0.001) when differentiating between no DR, non-proliferative DR, and proliferative DR.

Conclusion: DR grading SRIA and conventional fundus camera imaging were comparable. SRIA can be useful in eye screenings but still needs improvement.